Double coated tapes to be used for adhesion and fixation of members have been used in a vehicle and a housing as well as in the inside of electronic appliances. However, recently, problems of the use of these pressure sensitive adhesive tapes have been pointed out. For example, there occurs fogging attributed to high boiling point volatile components in glass in an automotive inside or operation failure attributed to high boiling point volatile components and impurities also in members of the inside of electronic appliances in some cases. Accordingly, a pressure sensitive adhesive tape to be used in closed space of vehicles such as automobiles and housings, electronic appliance insides is strongly required to be scarcely odorous and have a low total amount of volatile gases, which are environmental burden substances.
Meanwhile, in Japan, guidelines of decrease of respective interior volatile organic compounds but also decrease of the total of the volatile organic compounds for countermeasures for so-called sick houses in the housing field are issued from Ministry of Health, Labour, and Welfare. Also, German Association of the Automotive Industry (Verband der Automobilindustrie (VDA)) has determined an evaluation method for odors of members to be used for the automotive insides in VDA 270 and also evaluation methods for volatile components in DVA 277 and VDA 278. Further, in order to determine the behavior of the fog attributed to volatile components emitted from members, Deutsches Institut fur Normung has determined in DIN No. 75201. As described, it is required to decrease not only specific volatile substances but also a variety of volatile substances in various fields.
The causes of the volatile gases emitted from a common pressure sensitive adhesive tape may include a remaining solvent, a remaining monomer, a remaining polymerization initiator, a tackifier to be used for improving the pressure sensitive physical properties, and the like. Also, the causes of odors may include volatile gas and the like.
Japanese Kokai Publication Hei-6-122859 discloses a method for obtaining a pressure sensitive adhesive scarcely containing a remaining monomer by polymerizing a monomer having a high molecular weight and a low saturated steam pressure. Further, Japanese Kokai Publication Hei-2-115291 discloses a pressure sensitive adhesive using an acrylic polymer obtained by polymerization of a specific acrylic monomer to lower the odor. On the other hand, Japanese Kokai Publication 2002-69411 discloses a production method for a pressure sensitive adhesive tape comprising a pressure sensitive adhesive obtained by using a high purity acrylic polymer with few volatile components such as a remaining initiator or an unreacted monomer produced at a high polymerization ratio by solution polymerization at a specified reaction temperature using a specified amount of an azo type polymerization initiator. Japanese Kokai Publication 2002-309210 discloses a pressure sensitive adhesive tape at a low gas emission level obtained by block copolymerization. Further, Japanese Kokai Publication Hei-11-315260 discloses a production method for a hot melt type pressure sensitive adhesive tape as an anti-fogging pressure sensitive adhesive tape.
However, even in the case of these pressure sensitive adhesive tapes, there still remains a problem that in the case the tapes are used in closed space in housings, vehicles, the insides of electronic appliances, the odor suppression is insufficient by simply suppressing specific volatile components, so that the odor cannot be decreased to an insensible level. Also, high boiling point volatile components in the case of adding a tackifier are not taken into consideration and therefore, with respect to a common pressure sensitive adhesive containing the tackifier, no satisfactory effect has been achieved by conventional techniques.